Meaning

noun flavorful relish or dressing or topping served as an accompaniment to food

verb behave saucily or impudently towards

verb dress (food) with a relish

originPIE word *sḗh₂l From Middle English sauce, from Old French sause, from Vulgar Latin *salsa, noun use of the feminine of Latin salsus (“salted”), past participle of saliō (“to salt”), from sal. Doublet of salsa. For the meaning development compare Ancient Greek ἥδυσμα (hḗdusma) ultimately from Proto-Indo-European *swéh₂dus (whence also English sweet).

Etymology from Wiktionary, CC BY-SA 3.0